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(No Model.) Y I V W. A. GIBBS. ALARM DEVICE FOR BLEGTRIG MOTORS.

No. 568,608. Patentd Sept. 29, 1896.

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ATTORNEYS.

WITNESSES:

UNITED STAT {PATE T @rricn.

WALTER A. GIBBS, OF PAIVTUGKET, RHODE ISLAND.

ALARM DEVICE FOR ELECTRIC MOTQRS.

SPECIFICATION forming part of Letters Patent No. 568,608, dated September 29, 1896. Application filed Deoemh er1 4,18 95. Serial N... 572,218.: (No model.)

To all whom it may concern.-

Be it known that I, WALTER A. Games, of Pawtucket, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Alarm Devices for Electric Motors, of which the following is a full, clear, and exact description.

This invention relates to alarm devices for electric motors or similar devices in which an armature rotates within field-magnets, but my invention I design more particularly for motors on electric-railway cars, in which the motor is so inclosed in a frame or casing that the armature and shafting cannot be readily inspected to ascertain whether or not the armature is rotating evenly in its bearings.

The object of myinvention, therefore, is to provide a simple and comparatively inexpensive means for indicating when the armature from any cause whatsoever, whether from wear of bearings, displacement of bearin gs, or springing or buckling of shaft, touches 'a field-piece or stationary magnet of the motor.

I will describe a device embodying my invention, and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of thisspecification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a sectional elevation of a portion of a car and motor, showing the device embodying my invention. Fig. 2 is a sectional view of a motor, and showing the alarm and operating mechanism; and Fig. 3 is a section on the line 3 3 of Fig. 2, illustrating a modification.

Referring to the drawings, A designates the field-pieces of a motor, and A the armature therein. In the example of my improvement shown clearly in Fig. 2 each field-piece is provided at about its center, or in a vertical line with the armature-shaft, with a hole a, in which is inserted a bushing a of insulating material. For the purpose of rigidly securing the bushings they may be externally screwthreaded to engage corresponding threads in the holes. Extended through the bushing are electric terminals, here shown as made in the form of screw-plugs. The inner ends of the terminals are substantially flush with the in ner surfaces of the field-pieces, and from their outer ends wires 1 extend to a bearing-collar 2 on the shaft of a drop-target A The drop-target is here shown as made in the form of a quadrant, one half of its front surface being light in color and the other half being dark. A catch-plate 3 extends laterally from the central portion of the targets periphery. This catch-plate also serves as a contact-piece and is in connection, by means of a wire 4:, with the collar 2.

B is a pivoted armature-lever controlled by an electromagnet B and having a hook or latch extension I) for engagement with the catch-plate 3. One wire, 5, of the electromagnet is in electrical connection with the catch 1) and the other end, 6, of the wire is connected to one pole of a batteryB and from the other pole of the battery a wire 7 extends to the frame of the motor.

I have shown a battery for energizing the electromagnet B, but it is to be understood that the energy maybe taken from any other source, such, for instance, as from the driving-current of the motor. The target-battery and electromagnet may be located in any desired place in a car. I have here shown them as located beneatha seat and the front board thereof provided with an opening through Which one portion only of the target may be seen at one time.

In the example of my improvement shown in Fig. 3 the terminal is omitted from the upper field-piece, but two terminals 1) b are placed in the lower field-piece, nearits sides, so that, should a bearing for the armatureshaft be worn down, the terminal nearest the worn bearing will be engaged and the circuit closed to operate the target. In both forms of the improvement itwill be seen that the armature serves'as an automatic circuit closer. IV hen the circuit is closed through any cause, the electromagnet B will be energized to draw the armature-lever B, and consequently release the target, by a current passing through the wires 1 4:, the hook-latch b, the electromaguet, thence through the bottom of the frame of the motor and the arma ture.

It will be seen by using my device that every bearing may be used until it is abso lutely worn out, that no inspection of bearings for wear is necessary until the target indicates that inspection and adjustment is necessary, that the cost of applying'inydevice will be very little, and that the cost of its maintenance is practically nothing.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. An alarm for an electric motor, comprising an alarm device, an eleetromagnet for controlling the same, a source of electricity, a terminal extended through a field-piece and having its inner end substantially flush with the inner surface of the field-piece, a line-wire leading to said terminal, and the other li11e-wire connecting with the frame whereby the armature will serve as the other terminal substantially as specified.

2. An alarm for an electric motor, con1 prising an alarm device, a source of electricity, a terminal extended through each of the holdpieces, and insulated therefrom, both of said terminals being connected to one of the eircult-wires, and the other of said circuit-Wires being in electrical connection with the armature which serves as a terminal to coactwith cit-her of the first-named terminals, substantia-lly as specified.

\VALTEl-t A. GIBBS.

Witnesses:

Oscim LEWIS, H. F. TALL. 

